diff --git a/packages/core/src/runtime/dataspace.ts b/packages/core/src/runtime/dataspace.ts
index d1cc910..d4069b9 100644
--- a/packages/core/src/runtime/dataspace.ts
+++ b/packages/core/src/runtime/dataspace.ts
@@ -79,7 +79,7 @@ export class Dataspace implements Partial<Entity> {
     readonly options: DataspaceOptions;
     readonly index = new Index();
     readonly handleMap = new IdentityMap<Handle, Assertion>();
-    readonly observerMap = new IdentityMap<Ref, DataspaceObserver>();
+    readonly observerMap = new KeyedDictionary<Ref, Observe, DataspaceObserver>();
     readonly data = this;
 
     constructor(options?: DataspaceOptions) {
@@ -92,10 +92,9 @@ export class Dataspace implements Partial<Entity> {
         if (is_new) {
             const o = toObserve(strip(v));
             if (o !== void 0) {
-                const target = o.observer;
-                const observer = new DataspaceObserver(target);
-                this.observerMap.set(target, observer);
-                this.index.addObserver(o.pattern, observer, Turn.active);
+                const io = new DataspaceObserver(o.observer);
+                this.observerMap.set(o, io);
+                this.index.addObserver(o.pattern, io, Turn.active);
             }
             if (this.options.dumpIndex ?? false) this.index.dump();
         }
@@ -111,10 +110,10 @@ export class Dataspace implements Partial<Entity> {
         if (is_last) {
             const o = toObserve(strip(v));
             if (o !== void 0) {
-                const io = this.observerMap.get(o.observer);
+                const io = this.observerMap.get(o);
                 if (io !== void 0) {
                     this.index.removeObserver(o.pattern, io, Turn.active);
-                    this.observerMap.delete(o.observer);
+                    this.observerMap.delete(o);
                 }
             }
             if (this.options.dumpIndex ?? false) this.index.dump();